SuperDuper! Won't Quit
 

After SD! does a Smart Update, it remains open. Clicking to close it has no effect; telling it to quit hs no effect. The only way I can get it to quit is to force quit (cmd-option-esc).

(FWIW, when the Force Quit dialog box opens, the usual "not responding" statement next to the recalcitrant app does not appear next to SD!.)

Did I miss something in the manual?

If your situation happened after a scheduled backup (or a backup initiated through a custom AppleScript program) failed, it sounds like it could be a known bug caused by the conflicting conditions of SD! wanting to save the current settings, but not 'thinking' it may display UI prompts because of an automated invocation (see threads 3027, 3891, and 4550, among others that reference this bug).

Try saving the settings (Command+S or File > Save). Then all the normal ways of quitting should work again.

Thanks very much!

Yes, it sounds like that's what happened.

But the "schedule" window was also popping up indicating a backup failure; a Growl notification also indicated a failure, followed by another Growl notification indicating a subsequent success. (This was all happening at 1 AM, so I wasn't present to actually witness the sequence of events.)

I ended up clearing everything out and starting over again (effectively creating a new set of settings). Since then, everything's been working fine.

Again, many thanks for your help.